Is one who uses social media applications – such as Facebook, Imo, WhatsApp, Skype, any messaging app, or any media app [such as] mp3 or mp4 – in a manner that is impermissible, sinful? And is earning profit through them permissible?

There is no objection to promoting these means, for the sin of whoever misuses them in something unlawful falls upon him, not upon you, just like all other means that can be used for permissible or unlawful purposes. The basic ruling for them is permissibility, unless their use in unlawful activities becomes predominant. Jurists illustrate this with the example of grapes: cultivating and selling them is permissible, even if some people use them to make wine.